BMI Classification Percentile And Cut Off Points

Body mass index or BMI is a statistical index using a person's weight and height to provide an estimate of body fat in males and females of any age. It is calculated by taking a person's weight, in kilograms, divided by their height, in meters squared, or BMI = weight (in kg)/ height^2 (in m^2). The number generated from this equation is then the individual's BMI number. The National Institute of Health (NIH) now uses BMI to define a person as underweight, normal weight, overweight, or obese instead of traditional height vs. weight charts. These classifications for BMI are in use by the NIH and the World Health Organization (WHO) for White, Hispanic, and Black individuals. The cutoffs underestimate the obesity risk in the Asian and South Asian populations, so their classification has slight alterations. The BMI number and classifications are listed below. However, individual variations do exist, and BMI is insufficient as the sole means of classifying a person as obese or malnourished. In certain populations, like elite athletes and body-builders, an elevated BMI does not directly correlate to their health status due to their increased muscle mass and weight falsely increasing their BMI. Moreover, in the pediatric population, BMI allows comparison between children of the same sex and age. For children, a BMI that is less than the fifth percentile is underweight and above the 95th percentile is considered obese.